The following abbreviations and terms are herewith defined:                AP access point        Beacon receiver device receiving during the first DL period        Beacon transmitter device transmitting during the first DL period        BCH broadcast channel        BO beacon opportunity        BS base station (e.g., any generic network access node)        D2D device-to-device        DL downlink        eNB base station in an LTE/LTE-A system        E-UTRAN evolved UTRAN        LAE local area evolution (working name of a local radio access network including device-to-device communication)        LTE long term evolution of UTRAN (also known as 3.9 G)        LTE-A LTE advanced        OFDMA orthogonal frequency division multiple access        PBCH primary broadcast or beacon channel        PRS pseudo-random sequence        PSS primary synchronization sequence        RACH random access channel        RRM radio resource management        SRS sounding reference signal        SSS secondary synchronization sequence        UE user equipment (e.g., mobile or subscriber station SS/MS, terminal)        UL uplink        UMTS universal mobile telecommunications system        UTRAN UMTS terrestrial radio access network        WiMAX worldwide interoperability for microwave access        WLAN wireless local area network        
Future wireless communication systems are trending towards integrating network topologies rather than having multiple networks using different protocols overlying one another in the same geographic space. For example, there is some research into heterogeneous networks that are a deployment of macro, micro, pico, and/or femto cells and using relay nodes in the same LTE/LTE-A cellular overlay topology to all exploit the same radio spectrum. Another area of research in this integration concept is to allow direct communication between user devices when they are close to one another. This is often referred to as device-to-device D2D communications. At least the early conceptions of D2D communications use licensed radio spectrum that is specifically allocated by the cellular or other hierarchical network. One likely implementation for D2D is within a ‘home’ cell. Proposals for D2D variously are within WiMAX, HiperLAN 2, and Tetra protocols, to name a few non-limiting examples. For spectrum usage, it is also feasible that said heterogeneous networks or said D2D communications do not all utilize the same radio spectrum, but they share and divide among communication needs all the available radio spectrum in an efficient and reasonable manner, as allowed by regulations and licensing. In this kind of local use of radio spectrum, novel cognitive radio technology plays a significant role.
There is a need to establish D2D operation for data exchange between the devices in the coverage range. Prior art approaches often rely on the D2D devices being first authenticated to one another before broadcast messages can actually be exchanged between them. This leads to a large time delay from the initial state, when a message is ready to be sent to the time at which the other device is authenticated and a communication link between them is available for the transfer of user data.
Currently, D2D beacon opportunities are described only to exchange D2D and ad hoc network beacon messages and initiate handshaking for unicast message exchange for discovery, authentication and association messages. A broadcasting service is needed to enable new options for users and network operators, including location based marketing, creating local communities, local discussions and micro-blogging, pervasive games, and even local searches using a “local semantic web”.
One reference which may be relevant to these teachings is Danish patent application 2008E02868 DK, in which BSs are split into groups and continue sending the same message until all other BSs have potentially received the message. This method is designed for a case where each BS has information to send and every BS should receive the information of every BS.
Also relevant to these teachings is WO 09/018212, in which route discovery packets are flooded in the network. A broadcast buddy acknowledges the received broadcast message and ensures that at least one other device has received the message. U.S. Pat. No. 7,639,709 teaches that in a bootstrap period devices can make reservations for the usage of broadcast time slots.